2016-008 - Santa Ana Water Efficient Landscape Ordinance

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January 11, 2016 2.2 Water Efficient Landscape Calculations and Alternatives (A) The project applicant shall provide the calculated Maximum Applied Water Allowance (MAWA) and Estimated Applied Water Use (EAWU) for the landscape area as part of the Landscape Documentation Package submittal to the City. The MAWA and EAWU shall be calculated based on completing the Water Efficient Landscape Worksheets (in accordance with the sample worksheets in Appendix C) which contain information on the plant factor, irrigation method, irrigation efficiency and area associated with each hydrozone. Calculations are then made to show that the evapotranspiration adjustment factor (ETAF) for the landscape project does not exceed a factor of 0.55 for residential areas and 0.45 for non - residential areas, exclusive of Special Landscape Areas. The ETAF for a landscape project is based on the plant factors and irrigation methods selected. The Maximum Applied Water Allowance is calculated based on the maximum ETAF allowed (0.55 for residential areas and 0.45 for non - residential areas) and expressed as annual gallons required. The EAWU is calculated based on the plants used and irrigation method selected for the landscape design. (B) The EAWU allowable for the landscape area shall not exceed the MAWA. The MAWA shall be calculated using an evapotranspiration adjustment factor (ETAF) of 0.55 for residential areas and 0.45 for non - residential areas, except for the portion of the MAWA applicable to any Special Landscape Areas within the landscape project, which shall be calculated using an ETAF of 1.0. Where the design of the landscape area can otherwise be shown to be equivalently water - efficient, the project applicant may submit alternative or abbreviated information supporting the demonstration that the annual EAWU is less than the MAWA, at the discretion of and for the review and approval of the local agency. (C) Water budget calculations shall adhere to the following requirements: (1) The MAWA shall be calculated using the Water Efficient Landscape Worksheets and equation presented in Appendix C on page 25. The example calculation is a hypothetical example to demonstrate proper use of the equation. (2) The EAWU shall be calculated using the Water Efficient Landscape Worksheet and equations presented in page 26 of Appendix C. (3) For the calculation of the MAWA and EAWU, a project applicant shall use the ETo values from the closest location listed the Reference Evapotranspiration Table in Appendix D. For geographic areas not covered in Appendix D, data from other cities, or zip codes, located nearby in the same reference evapotranspiration zone may be used. (4) For calculation of the EAWU, the plant water use factor shall be detern7ined as appropriate to the project location from the Water Use